A bandpass channel, in the context of telecommunications and signal processing, is a communication channel that allows a specific range or band of frequencies to pass through while attenuating or blocking frequencies outside that range. It is the opposite of a bandstop or notch channel, which attenuates a specific range of frequencies while allowing others to pass. Bandpass channels are commonly used in various communication systems and applications, including wireless communication, radio, and audio processing. By selecting a particular frequency range or band for transmission, bandpass channels help isolate and transmit specific information while rejecting unwanted interference or noise.